A pair of twin brothers and sisters, born with evil spirits, run a weird paper-making shop called Banjianpu.
The downstairs belongs to yang, and it takes over the daily affairs of the mortal world; the upstairs belongs to yin, and a yin and yang inn is opened for lonely ghosts to stay.
The two brothers and sisters are proficient in the mystical arts of yin and yang, taking in the resentful and bloody souls, following layers of clues, and tearing apart the gray turbid web of the collusion between the evil forces of government, businessmen and the scum of Taoism.
Step into the mortal world, enter the underworld, and fight against evil.
The two of them have their own iron rules in their actions: they only punish the evildoers, do not harm those with good intentions, and specialize in dealing with the evil things that cannot be seen in the world.
